Omron CQM1H-SCB41 operation manual No-protocol Communications, 4 PC 11 Data Links

Basic Operating Procedure Section 1-2

•Pin 8 on the DIP switch on the front of the CQM1H-series CPU Unit must be turned ON to use the CX-Protocol. While pin 8 is ON, you will not be able to use any of the CPU Unit or Board ports for the CX-Programmer, SYSMAC-CPT, or SYSMAC Support Software.

•The model of PC must be set to the C200HG and the model of CPU Unit must be set to the CPU43.

•Refer to 5-2 Restrictions in Using the CX-Protocol for further details.

1-2-3 No-protocol Communications

The TXD(––) and RXD(––) instructions can be used in the ladder program to send and receive data without conversion through the RS-232C port to and from an external device.

A start code can be sent before the data and an end code can be sent after it. Alternately, the amount of data being sent can be specified. A communications frame, however, cannot be created according to the specifications of the partner device, providing less flexibility than protocol macros. Retry processing, data form conversions, controlling processing based on a response, and other com- munications procedures cannot be performed.

No-protocol communications are suitable for communications with bar code readers and other devices that only send data or printers and other devices that only receive data.

Note A 4-wire connection must be used when using an RS-422A/485 port.

Serial Communications Board

TXD(––) or

RXD(––)

CQM1H

External device with RS-232C port

RS-232C

OR

Data only

1-2-4 PC 1:1 Data Links

Two PCs can be connected via RS-232C cable to create a data link between them of up to 64 words in the LR area. The link words written by one PC are auto- matically transferred to the other PC for reading.

One of the following three ranges of words can be set to be linked:

LR 00 to LR 63, LR 00 to LR 31, or LR 00 to LR 15

A 1:1 Data Link communications system can be created between the CQM1H and another CQM1H, or between the CQM1H and the CQM1, C200HX/HG/HE, C200HS, CPM1, CPM1A, CPM2A, CPM2C, or SRM1(-V2).

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